1. Field of the Invention
The invention relates to a structure that joins a junction box and an electrical component connector block. The structure is configured so as to prevent material failure of the components that make up the connecting structure.
2. Description of the Related Art
Modern automobiles incorporate an increasing number of electrical components, which has resulted in an increase in the size of junction boxes used to connect electrical power and signal circuits, and increasingly complex junction box structures. As a result of this tendency toward larger and more complex junction boxes, and the requirement that junction boxes be capable of flexibly adapting to changes in the layout of circuits connected thereto, connecting structure must be provided to connect relay blocks, fuse blocks, and similar components to the junction box.
FIGS. 8A and 8B illustrate a conventional connecting structure for joining a junction box 1 and a relay block 4. In this structure, relay block 4 is joined to a junction box frame 2 through an insertion portion 5 located on an external sidewall 4b of relay block 4, and a receiver bracket 3 located on an external sidewall 2a of junction box frame 2. Relay block 4 is attached to junction box frame 2 by aligning insertion portion 5 over receiver bracket 3 and sliding relay block 4 downward. Attachment is complete when insertion portion 5 slides downward to a fully inserted position within receiver bracket 3, such that relay block 4 is aligned adjacent to junction box 1. A relay 4a can then be inserted into the upper surface of the attached relay block 4.
With relay block 4 attached to the junction box 1 in an adjacently aligned position, the force required to insert relay 4a into the relay block is applied as a leveraged load to receiver bracket 3 and insertion portion 5. As shown in FIG. 8C, external sidewall 2a of receiver bracket 3 is prone to material failure when a load greater than that required for insertion of the relay 4a is applied to the connecting components. If frame 2 of the junction box 1 is made from a glass impregnated resin, the connecting structure may fail more easily as a result of a load concentrated at a single point. The leverage force becomes more pronounced and the potential for material failure increases when multiple rows of relays 4a are installed onto the relay block 4, particularly during insertion of the outer row of relays 4a. Moreover, this type of failure may not only result from the insertion of relays 4a, but also from other objects striking or applying force to the relay block 4.
The present invention has been made in view of the above-described problems. Accordingly, it is an object of the present invention to provide a structure for joining an electrical component connector block, such as a relay block, fuse block, or similar component, to a junction box in adjacent alignment, wherein the connecting structure is not prone to material failure.
According to one aspect of the present invention, there is provided a connecting structure for adjacently joining a junction box and an electrical connector block, the connector block including a component receptacle portion on an upper surface thereof. The connecting structure includes connecting components provided on a sidewall of the junction box and a sidewall of the connector block, and a protruding hook portion provided on the connector block. The hook portion is configured to connect to an upper edge of the junction box sidewall. The protruding hook portion may be provided on the sidewall of the connector block.
According to a further aspect of the present invention, the hook portion distributes a force resulting from insertion of a component into the component receptacle portion of the connector block along the upper edge of the junction box sidewall.
Because the connecting structure forms a joint where the hook portion of the connector block engages a sidewall of the junction box, the force applied while pressing a component into the component receptacle portion is not concentrated on the connecting structure, but is instead distributed through the sidewall by the hook portion. As a result, the tendency for the connecting structure between the junction box and electrical connector block to materially fail is significantly reduced.
According to a further aspect of the present invention, the connecting components include a receiver bracket provided on the junction box sidewall and an insertion bracket provided on the connector block sidewall. The insertion bracket moves downward into the receiver bracket while the hook portion simultaneously moves downward to connect to the upper edge of the junction box sidewall. The receiver bracket may further include a lock latch and the insertion bracket may further include a lock tab configured to engage the lock latch for locking the connector block and the junction box in a connected condition. The attachment of the hook portion to the sidewall of the junction box occurs during joining of the electrical connector block and the junction box, providing an efficient attachment operation.
According to a further aspect of the present invention, the junction box sidewall includes first and second parallel sidewall portions having a space therebetween. The hook portion includes first and second hooks configured to connect to respective upper edges of the first and second parallel sidewall portions. This type of structure is able to further prevent material failure of the connecting structure by distributing the component insertion force to the first and second sidewall portions through the first and second hooks.
The connector block may be a relay block, and the component receptacle portion of the connector block may be configured to receive at least one relay inserted therein. The connector block may be a fuse block, and the component receptacle portion of the connector block may be configured to receive at least one fuse inserted therein.